Dane projektu

Całkowity koszt:

Niedostępne

Wkład UE:

Niedostępne

Kraj koordynujący:

Spain

Topic(s):

System finansowania:

CSC - Cost-sharing contracts

Cel

The main objective has been achieved by the development of a coating technique able to grow a thin, homogeneous and very well adhered layer of hydroxylapatite with controlled composition, density and crystallinity, without needing any grit-blasting pre-treatment of the pure Ti or Ti alloy. The PLD layer follows perfectly any geometry and topography of the surface, so that, within the project, plane, cylindrical and small animal hip prosthesis have been successfully coated.

The coatings have been produced by applying a new Pulsed Laser Deposition (PLD) method based upon an excimer laser beam focussed on an HA target. The ablated material forms a plume rendering film growth on a substrate located in front of it.

Adhesion strengths of the coatings without grit blasting have been greater than 58 MPa, and in all cases it was the bonding adhesive which failed. This result is specially interesting from the industrial point of view, since the main drawback of the conventional plasma spray (PS) method is the lacking of adhesion and subsequent spallation of the coating, resulting in major medical complications, such as implant loosening, severe inflammation, Etc.

In-vitro testing was performed for cytotoxicity and biocompatibility demostration, as well as screening of the coating with best potential for in-vivo performance. Cylindrical implants have been tested in rabbit tibia and dog jaw for comparison of the bone apposition at the PLD, plasma sprayed coated and the bare Ti surface. The results in rabbits gave several inflammatory cases for the plasma sprayed coated cylinders, while none for the PLD ones. The superior capability of our thin PLD coating in promoting osteointegration in the trabecular bone of rabbit tibia has been fully demonstrated, since the bone contact after 6 months was similar between bare Ti and the plasma sprayed one, but 43% more on the only 2 microns thick layer produced by our laser technique. This result opens great perspectives of revolutioning the field because until now the state of the art of the technology dictated plasma sprayed coatings of at least 50 microns, that had to be partially resorbed to promote bone bioactivity. We have demonstrated that a 2 microns thick, well adhered and homogeneous coating can perform better and after six months it hasn't resorbed, so that the thickness may well be still reduced.

The strategical industrial objective of the project was to obtain longer lasting and faster osteointegrable dental and orthopedic implants rendering great economical savings to the health institutions of the European Union by reducing the time of hospital care and convalescense and decreasing the number of traumatic operations for patients. These longer term objectives may now be envisaged on a shorter term in view of the excelllent results of this project, so that the consortium has already protected them by patenting the method for improved osteointegration. Additional industrial partners are presently sought to jointly work towards scaling up the results to construct an industrial laser coater and start the clinical trials.